Here's a deep dive into the Skarmorak fight of The Stonevault Dungeon including relevant mechanics and how to handle them in Mythic+.
The Stonevault Dungeon Overview
After Skarmorak casts Crystalline Smash on the Tank, three Crystal Shards will spawn around the arena. Each Crystal Shard left alive buffs Skarmorak's Fortified Shell, and so we want to destroy them. Whenever a Crystal Shard is destroyed, it inflicts Crystalline Eruption onto all players: a 3 second debuff that inflicts hefty damage. The unique part about Crystalline Eruption is that THE EFFECT STACKS which we ultimately want to avoid at all costs.
The proper way to handle the Crystal Shards mechanic is to destroy them as quickly as possible without stacking the Crystalline Eruption debuff. Once the first shard is destroyed, players will want to wait 3 seconds before destroying the next one and so on. Typically, players will want to focus the Crystal Shards in melee range first, then destroy any remaining shards that are further out in range. Handling the mechanic this way minimizes group damage taken by Crystalline Eruption and keeps Skarmorak's Fortified Shell from becoming any stronger.
Unstable Fragments appear as purple swirls that players will need to dodge after Skarmorak casts Unstable Crash. On Mythic, these Unstable Fragments leave behind purple motes after landing. Picking up these purple motes will grant players Unstable Energy, a 50% healing increase and 50% damage increase to Skarmorak's Fortified Shell. This buff lasts 30 seconds and can stack.
There is a small DoT effect that comes with having the Unstable Energy buff so be mindful not to grab too many stacks all at once!
With each set of Unstable Fragments, there are always 5 Unstable Energy motes that players can pickup. For pugs, we recommend everyone picking up at least one Unstable Energy mote per set. We will get a second